Question 1

What is the area code for Boulder?

Accepted Answer

The main area code for Boulder, Colorado is 303. Boulder is now served by 5 area codes in total: 303, 970, 720, 983, 748.

Question 2

How many area codes does Boulder have?

Accepted Answer

Boulder has 5 area codes: 303, 970, 720, 983, 748.

Question 3

Why does Boulder have more than one area code?

Accepted Answer

As Boulder used up the numbers available in its original area code (303, in service since 1947), additional "overlay" codes were added over the same area so new phone numbers could keep being assigned.

Question 4

How do you dial a Boulder number?

Accepted Answer

Dial all 10 digits — the area code (303 or 970 or 720 or 983 or 748) followed by the 7-digit local number. From outside the U.S., dial +1, then the area code and number.

Area codes in Boulder, Colorado

Area codes serving Boulder